1. Field of the Invention
The present invention relates in general to relay systems, and more particularly to an apparatus for monitoring grounded states of multiple direct current (DC) loads of a relay system, which is disposed in a DC power board.
2. Description of the Prior Art
Conventional apparatus for monitoring grounded states of multiple DC loads of a relay system, each of which is disposed in a DC power board, are merely operated in the case where a leakage current of each DC load flows exceeding a rating. However, some of the leakage currents of the multiple DC loads may be within the range of the rating, others may be beyond the range of the rating. For this reason, it is impossible to set the optimum leakage current suitably to a system characteristic. This results in an unnecessary interruption of power to the multiple DC loads. Also, a grounding current cannot be classified in polarity. One example of this form of apparatus for monitoring the grounded states of the multiple DC loads of the relay system is shown in product specifications (Model DGLR-30) available from SUN KWANG ELECTRIC Co., Ltd., Korea.